What is the refutation against someone who claims that the niqab - whether obligatory or recommended - has become off-putting in these times, and that it hinders a woman wearing niqab from engaging in da'wah (inviting to Islam) and reform?

The imams have agreed on the obligation of a woman covering her face when there is fear of fitna (temptation/strife) and corruption of the times. Society's view of the niqabi as being extremist can be changed through good character, patience, and educating people. Abandoning Shari'ah rulings under the pretext of people not accepting them weakens the religion. For those who adhere to them, there is a great reward, as they are among the "strangers" whom the Prophet, peace and blessings be upon him, described, and that patience in religion is like holding a burning coal. Therefore, the questioner should remain steadfast in her niqab and strive to seek knowledge and perform good deeds to be a good role model.